My laptop, Toshiba S870, equipped with a AMD Radeon HD7600M series graphics chip set, support two additional monitors? If so how do I hook them up?
Well. You need one monitor with VGA input and one monitor with HDMI input.
There is possibility to connect DVI or VGA monitor and HDMI output of laptop via HDMI to DVI (or VGA) adapter. But personally i don't recommend this variant.